package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }


    @Override
    public List<CategoryEntity> listWithTree(){
        //1.查出所欲分类
        List<CategoryEntity> entities = baseMapper.selectList(null);

        //2.组织父子的树形结构

        //2.1 找到所有的一级分类
        List<CategoryEntity> levelMenus = entities.stream().filter(categoryEntity ->
            categoryEntity.getParentCid() == 0     //如果分类id=0 说明是一级分类 并转换成list
        ).map((menu)->{
            menu.setChildren(getChildrens(menu,entities));
            return menu;
        }).sorted((menu1,menu2)->{
            return (menu1.getSort()==null?0:menu1.getSort())- (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());

        return levelMenus;
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {
        //检查当前删除的菜单 是否被别的地方引用
        baseMapper.deleteBatchIds(asList);

    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();
        List<Long> parentPath = findParentPath(catelogId, paths);

        Collections.reverse(parentPath);
        return parentPath.toArray(new Long[parentPath.size()]);
    }

    public List<Long> findParentPath(Long catelogId,List<Long>paths){
        //收集当前节点id
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        System.out.println("byId="+byId);

        if(byId.getParentCid()!=0){
            findParentPath(byId.getParentCid(),paths);
        }
        return paths;

    }

    //递归查找所有子菜单
    private List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> all){
        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
            return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEntity -> {
            //1. 找到子菜单
            categoryEntity.setChildren(getChildrens(categoryEntity, all));
            return categoryEntity;
        }).sorted((menu1, menu2) -> {
            //2.菜单的排序
            return (menu1.getSort()==null?0:menu1.getSort())- (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());

        return children;
    }
}